The present invention relates to a composition of alloys, such as naturally hard semifinished-material alloys, which are intended to be used in this form as material for structures.
Naturally hard aluminum alloys are used in metallurgy as semifinished materials for structures (see for example GOST standard 4784-74), but primarily in the form of AMg6 alloy, which contains the following (in percent by weight):
This alloy, however, does not have adequate physical properties, in particular a low 0.2% yield strength in the case of cold-formed and hot-formed semifinished materials.
A naturally hard aluminum alloy, which is used as a semifinished material for structures (see Russian Patent No. 2085607, IPC class C22 C 21/06), provides the following chemical composition (% by weight):
This alloy does not have sufficient static and dynamic strength, while having high processibility during the manufacturing process, high corrosion resistance, good weldability, and a high readiness for operation under low-temperature conditions.
The present invention is a new, naturally hard aluminum alloy for semifinished materials which, in addition to magnesium, titanium, beryllium, zirconium, scandium, and cerium, is also made of manganese, copper, zinc, and an element group containing iron and silicon, in the following composition of the components (weight %), the ratio of iron to silicon being in the range of 1 to 5:
FIG. 1 is a table of compositions of example embodiments of the present invention.
FIG. 2 is a table of properties of compositions of example embodiments of the present invention.
The alloy of the present invention is distinguished from other alloys by an addition of manganese, copper, zinc, and an element group containing iron and silicon, the components having the following proportions in weight percent, and with the ratio of iron to silicon between 1 and 5:
This alloy provides an improvement of the static and dynamic physical properties of the alloy. This results in the improvement of the service life, operational reliability, and weight value of the structures subjected to static and dynamic loads improve, in particular those of the structures of various aircraft and spacecraft, including craft that burn cryogenic fuel.
Due to the proportions of the present invention between the chemical levels and the chemical constituents, the alloy has a ductile matrix, which comprises a solid solution of dissolved magnesium, maganese copper, and zinc in aluminum.
The capability of the alloy for operation under cyclical dynamic loads is due to the high ductility of the matrix. Secondary precipitation of finely distributed intermetallic particles, which contain aluminum, scandium, zirconium, titanium, and other transition metals occurring in the alloy, provides for both the high static strength of the alloy and a high resistance to crack propagation during fatigue testing. The setpoint value of the ratio of iron to silicon optimizes the morphology of the primary intermetallic compounds, which result from the solidification, are principally made of aluminum, iron, and silicon, and provide for an improvement in the static strength of the alloy, while the dynamic strength and plasticity are maintained.